remove unused cache arguments

pkg/analysis_server/test/domain_completion_test.dart

 // Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library test.domain.completion;
 
 import 'dart:async';
 
 import 'package:analysis_server/src/analysis_server.dart';
 import 'package:analysis_server/src/channel/channel.dart';
@@ skipping 417 matching lines @@
 }
 
 class MockCache extends CompletionCache {
   MockCache(AnalysisContext context, Source source) : super(context, source);
 }
 
 class MockCompletionManager implements CompletionManager {
   final AnalysisContext context;
   final Source source;
   final SearchEngine searchEngine;
-  CompletionCache cache;
   StreamController<CompletionResult> controller;
   int computeCallCount = 0;
 
-  MockCompletionManager(this.context, this.source, this.searchEngine,
-      this.cache);
+  MockCompletionManager(this.context, this.source, this.searchEngine);
 
   @override
   void computeCache() {
     // ignored
   }
 
   @override
   void computeSuggestions(CompletionRequest request) {
     ++computeCallCount;
     CompletionResult result = new CompletionResult(0, 0, [], true);
@@ skipping 97 matching lines @@
             added: event.added.length > 0 ? [mockContext] : [],
             changed: event.changed.length > 0 ? [mockContext] : [],
             removed: event.removed.length > 0 ? [mockContext] : []));
   }
 
   void contextsChangedRaw(ContextsChangedEvent newEvent) {
     super.contextsChanged(newEvent);
   }
 
   CompletionManager createCompletionManager(AnalysisContext context,
-      Source source, SearchEngine searchEngine, CompletionCache cache) {
-    return new MockCompletionManager(mockContext, source, searchEngine, cache);
+      Source source, SearchEngine searchEngine) {
+    return new MockCompletionManager(mockContext, source, searchEngine);
   }
 }